Various forms of torque overload release drive units have been heretofore provided. However, most of these units are quite complicated in construction and others are of the friction drive coupling type whereby considerable sliding friction is encountered at and beyond the point of overload release. This considerable friction can result in rapid heat build up and resultant failure of the drive unit. Therefore, a need exists for an improved form of overload release.
Examples of torque overload release drive units utilizing some of the basic structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 1,807,210, 1,953,182, 2,335,574, 2,471,614, 2,690,090, 3,116,618, 3,472,347, and 3,487,902.